Regulator for underwater breathing apparatus

ABSTRACT

A regulator for an underwater breathing apparatus includes a housing defining a breathing cavity, a mouthpiece in communication with the breathing cavity, a valve operable to permit air from an air inlet of the regulator into the breathing cavity, and a sensor operable to measure a composition of air within one or both of the breathing cavity and the mouthpiece.

BACKGROUND

The present invention relates to systems for ensuring underwater diversafety, particularly with respect to nitrogen absorption. The inventionfurther relates to a regulator for an underwater breathing apparatusused by a diver.

The only resource for recreational divers to plan dive depth and divedurations are recreational dive planners. Recreational dive planners arebased on the projected nitrogen absorption rate into the body andgenerally allow for recreational divers to safely dive without gettingdecompression sickness (DCS). However, the projected nitrogen absorptionrates have been around for about 100 years, based on data fromexperiments conducted by the U.S. Navy, presumably on young, male diversin excellent physical condition. However, the published data is only aguide, as actual nitrogen absorption rates may vary from diver to diverand the nitrogen absorption rate of most recreational divers will varyfrom a theoretical standard diver on which the available data is based.Nitrogen absorption rates may even vary from male to female. Thus, itwould be beneficial to provide a means by which safe diving parametersmay be established without the inherent reliance on guesswork andhistorical data.

SUMMARY

In one aspect, the invention provides a regulator for an underwaterbreathing apparatus including a housing defining a breathing cavity, amouthpiece in communication with the breathing cavity, a valve operableto permit air from an air inlet of the regulator into the breathingcavity, and a sensor operable to measure a composition of air within oneor both of the breathing cavity and the mouthpiece.

In another aspect, the invention provides an underwater breathingapparatus including a regulator having a housing defining a breathingcavity, a mouthpiece in communication with the breathing cavity, a valveoperable to permit air from an air inlet of the regulator into thebreathing cavity, and a sensor operable to measure a composition ofcontents within one or both of the breathing cavity and the mouthpiece.The underwater breathing apparatus may also include a controllercommunicatively coupled to the sensor. The controller is configured tomonitor an output of the sensor to determine an amount of nitrogenabsorption in a user of the underwater breathing apparatus.

In yet another aspect, the invention provides a method of operating anunderwater breathing apparatus during a dive. The method includesopening a valve of a regulator to provide a breathing cavity of theregulator with air from an air inlet of the regulator, passing the airfrom the breathing cavity through a mouthpiece of the regulator forbreathing by a diver, measuring a composition of exhaled contents passedfrom the mouthpiece back into the breathing cavity with a sensor, anddetermining, with a controller, an amount of nitrogen absorbed by thediver based on an output of the sensor.

Other aspects of the invention will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an underwater breathing apparatus.

FIG. 2 is a top view of a secondary regulator of the apparatus of FIG.1.

FIG. 3 is a cross section view of a primary regulator and a secondaryregulator according to one embodiment of the invention.

FIG. 4 is a flow diagram of a method of measuring an amount of nitrogenabsorption of a diver during a dive.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways.

FIG. 1 illustrates an underwater breathing apparatus 10 configured for adiver to use while diving in an underwater environment. The underwaterbreathing apparatus 10 includes an air tank 14, a first stage regulator18 having an inlet 22 and a plurality of outlets 26, a pressure gauge 30operatively coupled to the air tank 14 and configured to display howmuch air is left in the air tank 14, a primary second stage regulator34, a secondary second stage regulator 38, a buoyancy compensator device(BCD) 49, and a plurality of hoses 42 to fluidly couple the pressuregauge 30, the primary and secondary second stage regulators 34, 38, andthe buoyancy compensator device 49 to the first stage regulator 18.

The air tank 14 contains compressed air which may have a composition ofat least 20 percent oxygen. In some embodiments, the composition of theair in the air tank 14 may be compressed atmospheric air (e.g., about 21percent oxygen and about 78 percent nitrogen, among other components)that has been filtered and dehumidified. In other embodiments, thecomposition of the air in the air tank 14 may be of air with a lowerpercentage of nitrogen and a higher percentage of oxygen (assuming acomposition such as that of “Enriched Air Nitrox”). For example, thecomposition may include 22 percent oxygen up to about 40 percent oxygen,with less than 78 percent nitrogen. In general, the air held within theair tank 14 may be any composition of oxygen, nitrogen, helium, amongother contents, that is breathable by humans when regulated to anappropriate pressure to allow a diver to remain and breathe underwaterfor an extended period of time. This may include Trimix (i.e., nitrogen,oxygen, helium blend) and Heliox (i.e., helium and oxygen blend) usedfor technical, non-recreational diving. Although it is recognized thatEarth's atmospheric air has one specific composition, all the variouscombinations described above are inclusively referred to herein as“air”, as it is well known to perform underwater diving with breathablecompositions other than the exact composition of Earth's atmosphericair.

Illustrated in FIG. 1, the first stage regulator 18 includes a number ofports, including high-pressure ports 22 (e.g., two high-pressure ports)and low-pressure ports 26 or outlets (e.g., four low-pressure ports).The air tank 14 is operatively coupled to the first stage regulator 18at one of the high-pressure ports 22 to function as an inlet to thefirst stage regulator 18. The additional high pressure port 22 may becoupled to the pressure gauge 30 to establish a connection between thepressure gauge 30 and the air tank 14 such that the pressure gauge 30 isoperable to measure and display a current air pressure of the air tank14. The first stage regulator 18 provides a first stage of pressurereduction of the compressed air in the air tank 14 to be incident ateach of the low-pressure ports 26. In other words, compressed air entersthe first stage regulator 18 at a first pressure from the air tank 14and exits the first stage regulator 18 from any of the utilizedlow-pressure ports 26 at a second pressure, which is lower than thefirst pressure. Each of the second stage regulators 34, 38 is coupled tothe first stage regulator 18 at a respective one of the low-pressureports 26 to establish breathing passageways from the air tank 14,through the first stage regulator 18, to the second stage regulator 34,38. Another of the low-pressure ports 26 can be coupled to an inflatorhose/power inflator of the buoyancy compensator device 49 as shown. Anadditional low-pressure port (not shown) can be coupled to a drysuitinlet for inflation of the drysuit.

Illustrated in FIG. 3, the first stage regulator 18 includes a pistonand spring assembly 46 configured to open and close a first-stage valve50 that supplies air at a lower pressure than the air in the air tank 14to the outlets 26 of the first stage regulator 18 through anintermediate passage 54. The intermediate passage 54 opens to the threeoutlets 26 so that air may be directed from the air tank 14 to thesecond stage regulators 34, 38 and the pressure gauge 30. For example,FIG. 3 shows the intermediate passage 54 coupled with the primary secondstage regulator 34.

Illustrated in FIGS. 2 and 3, each of the primary and secondary secondstage regulators 34, 38 includes a housing 58 having an air inlet 62 andan air outlet 66, a mouthpiece 70 shaped to be received in a diver'smouth, an air inlet valve 74, and an air outlet valve 78. The housing 58defines a breathing cavity 82. An interior cavity of the mouthpiece 70may also form part of the breathing cavity 82. The air inlet 62 isfluidly coupled to the first stage regulator 18 and is configured toreceive air from one of the outlets 26 through the hose 42. The airoutlet 66 is fluidly coupled with the ambient environment and isconfigured to dispel air from the breathing cavity 82 to the ambientenvironment. The mouthpiece 70 may be integrally formed with the housing58. In other embodiments, the mouthpiece 70 may be a separate elementthat is sealingly coupled to the housing 58. The mouthpiece 70 isgenerally coupled to the housing 58 such that the diver may inhale airfrom the breathing cavity 82, through the mouthpiece 70, as described ingreater detail below. The air outlet valve 78 is a flexible one-wayvalve configured to prevent contents of the ambient environment,especially water, from entering the breathing cavity 82.

The primary and secondary stage regulators 34, 38 may also include adiaphragm 86, positioned at one end of the housing 58, operable to openand close the air inlet valve 74 in response to a pressure differentialbetween the breathing cavity 82 and an ambient environment. Asillustrated in FIG. 3, the diaphragm 86 is coupled to the air inletvalve 74 by a linkage 90. In the illustrated embodiment of FIG. 3, theair inlet valve 74 includes a seal 94 and a spring 98 (e.g., compressionspring) to urge the seal 94 to cover the air inlet 62. The linkage 90 iscoupled to the seal 94 such that the seal 94 moves in response tomovement of the diaphragm 86 within the housing 58. In otherembodiments, the diaphragm 86 may push a lever to rotate the seal 94away from the air inlet 62.

In operation, when the diver inhales, the pressure in the breathingcavity 82 drops. When the pressure in the breathing cavity 82 dropsbelow that of the pressure of the ambient environment, the diaphragm 86flexes inward, moving the air inlet valve 74 away from the air inlet 62and allowing air to enter from the air tank 14. Air continues to flowfrom the air tank 14 into the breathing cavity 82 until the pressure ofthe breathing cavity 82 rises back to that of the ambient environment.The diaphragm 86 responds to the change of pressure in the breathingcavity 82 and returns to its original position, moving the linkage 90and the air inlet valve 78 as well. When the diver exhales, the pressureof the breathing cavity 82 becomes greater than that of the ambientenvironment. In response, the air outlet valve 78 flexes outwardallowing exhaled air to flow from the breathing cavity 82 to the ambientenvironment. As similarly stated above, the outlet valve 78 returns toits original position when the pressure of the breathing cavity 82returns to balance with the pressure of the ambient environment.

Illustrated in FIG. 3, the primary second stage regulator 34 alsoincludes a first sensor 102 and a second sensor 106. The first sensor102 and the second sensor 106 are operable to measure a composition ofair entering and exiting the breathing cavity 82 of the primary secondstage regulator 34. For example, the first and second sensors 102, 106may each respectively operate to determine a percentage of nitrogen inthe air supplied to the diver for breathing and the exhaled contents or“exhaled air” from the diver. The first sensor 102 and the second sensor106 may be any one or a combination of a nitrogen sensor, an oxygensensor, a carbon dioxide sensor, and a helium sensor. The first sensor102 and the second sensor 106 may be any sensor that allows a controller110 or dive computer 114, each described in greater detail below, todetermine an amount of nitrogen that is absorbed by the diver during thedive. The first and second sensors 102, 106 may be configured todetermine nitrogen content in real time in order to quantify nitrogenabsorption by the diver in real time to provide an actual measure onwhich to base one or more dive parameters (e.g., depth, duration).

As shown in the illustrated embodiment of FIG. 3, the first sensor 102may be positioned in the breathing cavity 82 and just outside of andadjacent to the mouthpiece 70. In other embodiments, the first sensor102 may be positioned within the interior of the mouthpiece 70 orpositioned adjacent the air outlet 66. In some embodiments, a sensor maybe positioned within the interior of the mouthpiece 70 in addition tothe first sensor 102 positioned in the breathing cavity 82, thusresulting in two sensors measuring the composition of exhaled contentsfrom the diver. In general, the first sensor 102 is positioned betweenthe mouthpiece 70 and the air outlet 66 so as to measure the compositionof the air in the breathing cavity 82 when the air within the breathingcavity 82 is air that has been exhaled by the diver, as explained ingreater detail below. Further illustrated in the embodiment of FIG. 3,the second sensor 106 may be positioned in the breathing cavity 82,adjacent the air inlet 62. In other embodiments, the second sensor 106may be positioned farther upstream of the air inlet 62 of the air inlet62 or within the mouthpiece 70. In some embodiments, a sensor may bepositioned upstream of the air inlet 62 or within the mouthpiece 70, inaddition to the second sensor 106 positioned in the breathing cavity 82,thus resulting in two sensors measuring the composition of the airsupplied to the breathing cavity 82. In general, the second sensor 106is positioned between the air inlet 62 and the mouthpiece 70 so as tomeasure the composition of the air when the air within the breathingcavity 72 is being inhaled by the diver, as explained in greater detailbelow. In other embodiments, the primary second stage regulator 34 mayinclude only the first sensor 102 for measuring nitrogen content. Forexample, if the composition of the air in the air tank 14 is known, thesecond sensor 106 is redundant, and may be eliminated in someembodiments.

The underwater breathing apparatus further includes a controller 110 anda dive computer 114. In some embodiments, the controller 110 is includedin the dive computer 114. In other embodiments, the controller 110 andthe dive computer 114 are separate components. The controller 110 iscommunicatively coupled to the first and second sensors 102, 106 and isconfigured to monitor outputs of the first and the second sensors 102,106 to determine an amount of nitrogen absorption in the diver. Thecontroller 110 is operable to determine the amount of nitrogenabsorption in the diver by comparing the amount of nitrogen the diverinhales with the amount of nitrogen the diver exhales during eachbreathing cycle (i.e., one inhale and one exhale). For each breathingcycle, the controller 110 may determine the amount of nitrogen retainedby the diver and may update a value of the amount of retained nitrogenso as to keep a running sum of the nitrogen absorption in the diver. Insome embodiments, the controller 110 may incorporate a timer todetermine a rate of nitrogen absorption within the diver.

The controller 110 may be configured to recognize when the diver isinhaling by monitoring the position of the air inlet valve 74, thediaphragm 86, the linkage 90, or by comparing the pressure of thebreathing cavity 82 with the pressure of the ambient environment. Thecontroller 110 may be configured to recognize when the diver is exhalingby monitoring the position of the position of the air outlet valve 78 orby comparing the pressure of the breathing cavity 82 with the pressureof the ambient environment.

In one embodiment, to determine the amount of nitrogen the diverexhaled, the controller 110 may record the output of the first sensor102 during an exhale and may also measure the amount of time the diverexhaled by one of the methods explained above. The controller 110 mayestimate the amount of nitrogen exhaled by the diver by multiplying theduration of the exhale by the recorded output of the first sensor 102 ata point in time during the exhale. The controller 110 may also moreaccurately estimate the amount of nitrogen exhaled by entering theduration of the exhale and the output of the first sensor 102 into aformula and then determining the output of the formula. Alternatively,the first sensor 102 may continuously output data and the controller 110may continuously monitor the output of the first sensor 102 to determinethe amount of nitrogen exhaled by the diver.

In one embodiment, to determine the amount of nitrogen the diverinhaled, the controller 110 may record the output of the second sensor106 during an inhale and may also measure the amount of time the diverinhaled by one of the methods explained above. The controller 110 mayestimate the amount of nitrogen inhaled by the diver by multiplying theduration of the inhale by the recorded output of the second sensor 106at a point in time during the inhale. The controller 110 may also moreaccurately estimate the amount of nitrogen inhaled by entering theduration of the inhale and the output of the second sensor 106 into aformula and then determining the output of the formula. Alternatively,the second sensor 106 may continuously output data and the controller110 may continuously monitor the output of the second sensor 106 todetermine the amount of nitrogen inhaled by the diver.

The dive computer 114 is generally configured to monitor the running sumof the nitrogen absorption in a diver to prevent the diver from gettingsick from the dive. The dive computer 114 may have a stored value of howmuch nitrogen a diver may absorb before getting decompression sickness,or other problems, from prolonged dives or dives at great depth. Thecontroller 110 may be configured to update the running sum of thenitrogen absorption in the dive computer 114 so that the diver may bemade aware by the controller 110 or the dive computer 114 of how muchmore nitrogen they may absorb or how long they may safely remain at thecurrent depth or other various depths before they must return thesurface.

The dive computer 114 may have a stored value for the amount of nitrogenabsorption considered safe for each individual diver. The stored valuemay be dependent on the diver's physiology (e.g., weight, body massindex, height, etc.), age, gender, diving history, among other things.Alternatively, the dive computer 114 may have a preprogrammed diveschedule, irrespective of the diver, which may correspond to how long adiver may safely remain at certain depths determined by the rate ofnitrogen absorption at each depth. The controller 110 or the divecomputer 114 may be configured to update a dive schedule for the diverin response to the measured nitrogen absorption. The diver's diveschedule may include information such as the allowable, safe dive timeat certain depths. The controller 110 or the dive computer 114 maymeasure an amount of nitrogen absorption and inform the diver how thediver must surface (i.e., rate of ascent and the duration required atrespective depths during ascent) in order to surface safely. The amountof nitrogen absorption could be used for updating how long until thediver may dive again. The amount of nitrogen absorption may be used bythe dive computer 114 to determine the amount of dive time remaining ateach depth or in total.

Although described above as being used in conjunction with a storedvalue of safe nitrogen consumption or dive schedule, the overallnitrogen absorption by the diver, determined by the controller 110 andthe dive computer 114, may be used in a number of different ways todetermine how each diver may remain safe (e.g., to prevent decompressionsickness) during their respective dives.

Although shown as being used with the pressure gauge 30, the air tank14, the secondary second stage regulator 38, and the first stageregulator 18, it should be understood that the primary second stageregulator 34, the controller 110, and the dive computer 114 may be usedindependently of the above-described underwater breathing apparatus 10.For example, the primary second stage regulator 34 may be used with thecontroller 110 and the dive computer 114 for surface supplied diving,wherein there is a large supply of air at the surface of the water forthe diver to use. In this case, it may be beneficial for the diver tomore closely monitor the amount of nitrogen absorption as the amount ofair available to the diver is less significant for diving times. Inother embodiments, the first sensor 102, the second sensor 106, thecontroller 110, and the dive computer 114 may be used as described abovewith other diving components in other diving methods, such as with arebreather.

Thus, the disclosure provides, among other things, a regulator for anunderwater breathing apparatus for determining an amount of nitrogenabsorption by a diver. Various features and advantages of the disclosureare set forth in the following claims.

What is claimed is:
 1. A regulator for an underwater breathingapparatus, the regulator comprising: a housing defining a breathingcavity; a mouthpiece in communication with the breathing cavity; a valveoperable to permit air from an air inlet of the regulator into thebreathing cavity; and a sensor operable to measure a composition of airwithin one or both of the breathing cavity and the mouthpiece.
 2. Theregulator of claim 1, further comprising a diaphragm operable to openand close the valve in response to a pressure differential between thebreathing cavity and an ambient environment.
 3. The regulator of claim1, wherein the valve is a first valve, and wherein the regulator furthercomprises a second valve operable to selectively establish fluidcommunication between the breathing cavity and an ambient environmentwhen the pressure in the breathing cavity exceeds the pressure of theambient environment.
 4. The regulator of claim 1, wherein the sensor isa first sensor, and wherein the regulator further comprises a secondsensor operable to measure at least one portion of the composition ofair supplied into the breathing cavity from the air inlet.
 5. Theregulator of claim 4, wherein the first sensor is positioned between themouthpiece and an outlet valve of the regulator that is operable toallow exhaled contents to flow from the breathing cavity to an ambientenvironment, and the second sensor is positioned between the air inletand the mouthpiece.
 6. The regulator of claim 4, wherein the firstsensor and the second sensor are operable to measure a differential ofnitrogen content between the composition of air supplied into thebreathing cavity from the air inlet and the composition of air expelledfrom the mouthpiece into the breathing cavity.
 7. The regulator of claim4, wherein the second sensor is positioned upstream of the air inlet. 8.The regulator of claim 1, wherein the sensor is positioned in thebreathing cavity.
 9. The regulator of claim 1, wherein the sensor ispositioned in the mouthpiece.
 10. An underwater breathing apparatuscomprising: a regulator including a housing defining a breathing cavity,a mouthpiece in communication with the breathing cavity, a valveoperable to permit air from an air inlet of the regulator into thebreathing cavity, and a sensor operable to measure a composition ofcontents within one or both of the breathing cavity and the mouthpiece;and a controller communicatively coupled to the sensor, wherein thecontroller is configured to monitor an output of the sensor to determinean amount of nitrogen absorption in a user of the underwater breathingapparatus.
 11. The underwater breathing apparatus of claim 10, whereinthe regulator further includes a diaphragm operable to open and closethe valve in response to a pressure differential between the breathingcavity and an ambient environment.
 12. The underwater breathingapparatus of claim 10, wherein the controller is operable to compare anoutput of the sensor during a first condition, in which the valve isopen to allow air to flow into the breathing cavity from the air inlet,with an output of the sensor during a second condition, in which anoutlet valve of the regulator is open to allow exhaled contents to flowfrom the breathing cavity to an ambient environment.
 13. A method ofoperating an underwater breathing apparatus during a dive, the methodcomprising: opening a valve of a regulator to provide a breathing cavityof the regulator with air from an air inlet of the regulator; passingthe air from the breathing cavity through a mouthpiece of the regulatorfor breathing by a diver; measuring a composition of exhaled contentspassed from the mouthpiece back into the breathing cavity with a sensor;and determining, with a controller, an amount of nitrogen absorbed bythe diver based on an output of the sensor.
 14. The method of claim 13,wherein the amount of nitrogen absorbed by the diver is determined bycomparing a percentage of nitrogen measured in the composition ofexhaled contents to a percentage of nitrogen in the air provided to theregulator.
 15. The method of claim 13, wherein the valve is a firstvalve, and wherein the composition of exhaled contents is measuredduring a first condition, in which the first valve is closed and asecond valve of the regulator is open to allow the exhaled contents toflow from the breathing cavity to an ambient environment.
 16. The methodof claim 15, wherein the method further comprises measuring acomposition of the air provided to the breathing cavity from the airinlet during a second condition, in which the second valve is closed andthe first valve is open to allow air to flow into the breathing cavityfrom the air inlet.
 17. The method of claim 16, wherein the methodfurther comprises measuring a differential of nitrogen content betweenthe composition of the air provided to the breathing cavity from the airinlet during the second condition with the composition of exhaledcontents provided to the breathing cavity from the mouthpiece during thefirst condition, and wherein the amount of nitrogen absorbed by thediver is determined by the differential of nitrogen content.
 18. Themethod of claim 13, wherein the valve of the regulator opens in responseto the pressure of the breathing cavity being less than ambientpressure.
 19. The method of claim 13, wherein the composition of exhaledcontents is measured at one or both of the mouthpiece and the breathingcavity by the sensor.
 20. The method of claim 13, wherein the methodfurther comprises updating a dive schedule based on the determinedamount of nitrogen absorbed by the diver.